Hey Downunder, you agree with Dar?
I too use up to 30% oil for that first run. Color me oldfashioned because The extra oil is castor. I use up any old batch of fuel I have around in the process, since performance is yet to come.
When the engine limbers up my curiosity wins, and I put good fuel in, together with a new plug, and lean out the d*** thing to best rpm, just long enough to get a tach reading. When satisfied with the thereafters, I go fly it, dive to screaming rpm, fly and dive again.